copy-object: Do not use ETag of source as MD5 as it will not be MD5 if source was uploaded as multipart. (#2938)
copy-object: Do not use ETag of source as MD5 as it will not be MD5 if source was uploaded as multipart. (#2938)

fixes #2934
brendanashworth/minio,minio/minio,fwessels/minio,luomeiqin/minio,brendanashworth/minio,rushenn/minio,harshavardhana/minio,koolhead17/minio,mf-00/newgo,dvstate/minio,jimjag/minio,dvstate/minio,brendanashworth/minio,abperiasamy/minio,mf-00/newgo,balamurugana/minio,hackintoshrao/minio,krishnasrinivas/minio-daily,rushenn/minio,krisis/minio,harshavardhana/minio,aead/minio,aead/minio,vadmeste/minio,krishnasrinivas/minio,rushenn/minio,dutchcoders/minio,aead/minio,luomeiqin/minio,krishnasrinivas/minio-daily,donatello/minio,jimjag/minio,dutchcoders/minio,harshavardhana/minio,hackintoshrao/minio,krishnasrinivas/minio,fwessels/minio,hackintoshrao/minio,dutchcoders/minio,alexellis/minio,balamurugana/minio,harshavardhana/minio,abperiasamy/minio,krisis/minio,harshavardhana/minio,abperiasamy/minio,NitishT/minio,abperiasamy/minio,harshavardhana/minio,jimjag/minio,koolhead17/minio,luomeiqin/minio,dutchcoders/minio,brendanashworth/minio,fwessels/minio,minio/minio,krishnasrinivas/minio,aead/minio,aead/minio,alexellis/minio,aead/minio,aead/minio,dvstate/minio,NitishT/minio,hackintoshrao/minio,harshavardhana/minio,rushenn/minio,fwessels/minio,luomeiqin/minio,NitishT/minio,NitishT/minio,krishnasrinivas/minio,jimjag/minio,donatello/minio,vadmeste/minio,aead/minio,harshavardhana/minio,dvstate/minio